ALS-LIKE DISEASE ATTRIBUTED TO HIV INFECTION

Two new studies show that the AIDS virus, HIV, can cause a version of amyotrophic lateral sclerosis (ALS) that's treatable with commonly used anti-HIV drugs.

For people with ALS — a fatal neurodegenerative disease that has no cure — the studies could lead to routine HIV testing and, in those who test positive, a remarkably improved prognosis.

The studies describe several HIV-positive adults who developed an ALS-like syndrome as the first manifestation of AIDS, but largely recovered from the syndrome after receiving treatments that decreased their viral loads.

The ALS-like syndrome has some distinctions from "classic" ALS, including an earlier age of onset and a more rapid progression. Those distinctions, combined with the fact that only a small fraction of people who are HIV-positive developed the syndrome, indicate that HIV probably isn't a major cause of ALS, experts say.

Still, they suspect that some instances of sporadic ALS — the 90 percent of ALS cases that aren't caused by genetic factors — might be traced to HIV, and then effectively treated with anti-HIV medication.

"This isn't going to affect a huge number of ALS patients, but in anyone who is a little unusual or atypical [in age or disease progression], we should look for HIV," said neurologist Burk Jubelt, co-director of the MDA clinic at the State University of New York in Syracuse. Jubelt specializes in neurovirology — the study of viruses that attack the nervous system — and sees ALS patients in his clinical practice.

Although HIV infection is ultimately fatal, "there are patients with HIV infection who've been receiving treatment and remained stable for many years," Jubelt said. Usually, ALS is fatal within three to five years of diagnosis.

In one of the new studies, French researchers found that six of 1,700 HIV-positive people had an ALS syndrome. With anti-HIV medication, all improved and two fully recovered from the syndrome.

In a second study, researchers at Beth Israel Medical Center in New York reported that a woman with the syndrome was largely free of ALS symptoms after four years of anti-viral treatment. Both studies appear in the Sept. 25 issue of Neurology, along with an editorial by Jubelt.

In addition to showing a link between HIV and ALS, the studies might bolster a controversial theory that the enterovirus family of viruses can cause ALS. A group of French researchers found evidence for enteroviral infection in autopsies from French ALS patients, but a later study of American ALS patients failed to replicate those findings.

Although HIV isn't an enterovirus, the new studies "might provoke more work on animal models of viral infection and ALS," Jubelt said.

"There could even be viruses that cause ALS that we haven't identified yet," Jubelt said.

In light of that possibility, the new studies could justify clinical trials of anti-viral drugs for ALS, even in ALS patients who are HIV-negative, he said.